US 3,973,697 A · Adhesive gun

Abstract

A thermoplastic material dispensing apparatus adapted to translate feedstock from a solid state to a molten state by a novel heater block structure, and to discharge the molten feedstock through a novel discharge valve in response to operation of a novel trigger device. A novel annular cooling chamber is established about the dispenser's barrel to maintain a solid/melt interface inside the barrel adjacent to the heater block structure, that zone being air cooled by inlet air taken from a single inlet air line. The inlet air from the single line also drives the dispenser's ram through use of a novel pneumatic motor/spool valve mechanism. The spool valve is manually stroked forward to extend the dispenser's ram for extruding the feedstock, and is manually stroked rearward to retract the ram for recharging. Other features include a novel visual telltale that disappears when recharging of the dispenser is desirable, and a novel safety interlock that prevents exposure of the charging port for recharging unless the dispenser's ram has been fully retracted and that insures retention of the ram in that fully retracted position while the charging port is so exposed.

Claims17

Dependent claims

A device adapted to translate a feedstock such as a thermoplastic adhesive from a solid state to a molten state, comprising

a barrel having a ram axially extendable and retractable therein,
a ram motor having a piston head located within a motor housing, and
control valve means adapted to alternatively deliver and exhaust motive fluid with respect to at least one face of said piston head,
said control valve means including a manually actuatable spool valve contained in said motor housing, said spool valve having a transfer bore axially disposed therethrough, the opposing end faces of said spool valve being of equal area, and
said spool valve being aligned axially parallel with said barrel such that manual stroking of said spool valve forward serves to positively drive said ram within said barrel in the forward direction, and manual stroking of said spool valve rearward serves to drive said ram in the aft direction.

2 more elements

A device adapted to translate a feedstock such as a thermoplastic adhesive from a solid state to a molten state, comprising

a barrel having a ram axially extendable and retractable therein,
a ram motor having a piston head located within a motor housing, and
control valve means adapted to alternately deliver and exhaust motive fluid with respect to at least one face of said piston head,
a telltale cooperatively associated with said ram that indicates when recharging of said barrel should take place, the indication being triggered by a specific extended location of said ram inside said barrel, and
said telltale extending exteriorly of the motor housing, said telltale being movable relative to said ram, and said telltale being mechanically actuated by said ram so as to withdraw said telltale interiorly of the motor housing as said ram is extended to that location within said barrel where recharging of the device should take place.

2 more elements

Dependencies are inferred from the claim text.

Adhesive gun

Life of this patent

Adhesive gun

Life of this patent

Abstract

Claims17